Blenders or food processors have a blade or blades which are positioned in a container or pitcher and which are driven by a motor. Traditionally, a drive coupler is used to couple the shaft of the motor to the shaft carrying the blade. A typical prior art coupler is merely threaded onto the motor shaft in a fashion such that when the motor rotates, the coupler will become tighter on the shaft rather than loosen from the shaft. After some usage, however, these drive couplers wear out and need to be replaced. Such is not an easy task because when one engages and turns the coupler, the entire motor shaft merely rotates, thereby not loosening the coupler from the shaft. To loosen the coupler, the machine must be disassembled to gain access to the armature of the motor so that it can be held while the coupler is removed from the shaft and replaced. Then, of course, the machine must be re-assembled.
A reasonable prior art solution to this problem is to provide a notch on the motor shaft which is engaged by a set screw which can extend through the coupler. While this system may be more convenient than that described above, the installation and replacement procedures for these types of couplers are not without their difficulties. For example, the coupler is hidden by a cosmetic cover, and the set screw on the coupler must be aligned with a hole in the cover so that access to the set screw can be obtained. Then when the coupler is replaced, the set screw is tightened all the way and then backed-off a bit to advantageously allow for some play so that the coupler will self-center. Then the hole in the cover must be filled with a silicone material to avoid contamination. Such is a somewhat tedious and time consuming project.
Thus, the need exists for a drive coupler which can easily and quickly be removed from and attached to the shaft of a motor.